Muffer: RLV 4100, 4102, or 4104 - .1285 no go on baffle holes. No coatings allowed on muffler. Must be removable.

OR:

Optional Header/Muffler: Single stage, .75” Max OD, .635” Max ID header with RLV Mini 91 with threaded nipple. Must be threaded on end of header and removable. Maximum length of header and muffler is 15” and minimum is 10”.